在使用Java Swing的独立应用程序中，我使用ResultSet遍历Excel工作表（后端数据）。但是在执行插入查询后，当我尝试再次使用ResultSet遍历记录时，它会显示“ResultSet已关闭”。之后不能执行任何操作 错误是什么？我找不到它了。请告诉我。我是新手..所以请简单解释一下。我很感谢你的帮助。谢谢:)）
public sowui(String s)
{
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
con=DriverManager.getConnection("jdbc:odbc:test");
Statement stmt = con.createStatement();
stmt = con.createStatement( ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE );
String sql ="SELECT * FROM [Sheet1$] ";
rs =stmt.executeQuery(sql);
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
setTitle("MANAGEMENT OF STATEMENT OF WORKS");
setLayout(null);
l1=new JLabel("CONTRACT REFERENCE NUMBER");
t1=new JTextField(20);
l1.setBounds(50,100,250,50);
t1.setBounds(300,110,135,30);
t1.addKeyListener(new KeyAdapter() {
public void keyTyped(KeyEvent e) {
String input=t1.getText();
Pattern p = Pattern.compile("[A-Z,a-z,&%$#@!()*^]");
Matcher m = p.matcher(input);
if (m.find()) {
t1.setText(null);
JOptionPane.showMessageDialog(null, "Please enter only numbers");
}
} });
l1m=new JLabel("*");
l1m.setBounds(260,100,10,50);
l1m.setForeground(Color.RED);
l2=new JLabel("CR NUMBER");
final String [] crn = {"N/A"};
c6 =new JComboBox(crn);
c6.setEditable(true);
c6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("comboBoxEdited")) {
System.out.println("Adding new player!");
c6.insertItemAt(c6.getSelectedItem(),0);
}
}
});
l2.setBounds(50,150,250,50);
c6.setBounds(300,160,135,30);
l2m=new JLabel("*");
l2m.setBounds(130,150,10,50);
l2m.setForeground(Color.RED);
l3=new JLabel("SOW NAME");
t3=new JTextField(20);
t3.addKeyListener(new KeyAdapter()
{
public void keyTyped(KeyEvent e) {
String input=t3.getText();
Pattern p = Pattern.compile("[0-9]");
Matcher m = p.matcher(input);
if (m.find())
{
t3.setText(null);
JOptionPane.showMessageDialog(null,"Enter only characters A-Z or a-z");
}
}
});
l3.setBounds(50,200,250,50);
t3.setBounds(300,210,135,30);
l3m=new JLabel("*");
l3m.setBounds(120,200,10,50);
l3m.setForeground(Color.RED);
l4=new JLabel("PARTNER SERVICE MANAGER");
t4=new JTextField(20);
t4.addKeyListener(new KeyAdapter()
{
public void keyTyped(KeyEvent e) {
String input=t4.getText();
Pattern p = Pattern.compile("[0-9]");
Matcher m = p.matcher(input);
if (m.find())
{
t4.setText(null);
JOptionPane.showMessageDialog(null,"Enter only characters A-Z or a-z");
}
}
});
l4.setBounds(50,250,250,50);
t4.setBounds(300,260,135,30);
l4m=new JLabel("*");
l4m.setBounds(230,250,10,50);
l4m.setForeground(Color.RED);
l5=new JLabel("LBG SERVICE MANAGER");
t5=new JTextField(20);
t5.addKeyListener(new KeyAdapter()
{
public void keyTyped(KeyEvent e) {
String input=t5.getText();
Pattern p = Pattern.compile("[0-9]");
Matcher m = p.matcher(input);
if (m.find())
{
t5.setText(null);
JOptionPane.showMessageDialog(null,"Enter only characters A-Z or a-z");
}
}
});
l5.setBounds(50,300,250,50);
t5.setBounds(300,310,135,30);
l5m=new JLabel("*");
l5m.setBounds(200,300,10,50);
l5m.setForeground(Color.RED);
l6=new JLabel("TYPE OF CONTRACT");
final String [] tct = {"SOW"};
c4 =new JComboBox(tct);
c4.setEditable(true);
c4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("comboBoxEdited")) {
System.out.println("Adding new player!");
c4.insertItemAt(c4.getSelectedItem(),0);
}
}
});
l6.setBounds(50,350,250,50);
c4.setBounds(300,360,135,30);
l6m=new JLabel("*");
l6m.setBounds(180,350,10,50);
l6m.setForeground(Color.RED);
l7=new JLabel("VALUE OF CONTRACT");
t7=new JTextField(20);
t7.addKeyListener(new KeyAdapter() {
public void keyTyped(KeyEvent e) {
String input=t7.getText();
Pattern p = Pattern.compile("[A-Z,a-z,&%$#@!()*^]");
Matcher m = p.matcher(input);
if (m.find()) {
t7.setText(null);
JOptionPane.showMessageDialog(null, "Please enter only numbers");
}
} });
l7.setBounds(50,400,250,50);
t7.setBounds(300,410,135,30);
l7m=new JLabel("*");
l7m.setBounds(190,400,10,50);
l7m.setForeground(Color.RED);
l8=new JLabel("REMARKS");
t8=new TextArea(15,40);
l8.setBounds(50,450,250,50);
t8.setBounds(300,460,200,80);
l9=new JLabel("WORK STATUS");
final String [] workstatus = {"Live","Pipeline","Working at Risk"};
c1 =new JComboBox(workstatus);
c1.setEditable(true);
c1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("comboBoxEdited")) {
System.out.println("Adding new player!");
c1.insertItemAt(c1.getSelectedItem(),0);
}
}
});
l9.setBounds(500,100,250,50);
c1.setBounds(750,110,135,30);
l9m=new JLabel("*");
l9m.setBounds(600,100,10,50);
l9m.setForeground(Color.RED);
l10=new JLabel("CONTRACT APPROVAL");
final String [] cal = {"Fully signed off","WithPlatform","with partner for signoff"};
c2 =new JComboBox(cal);
c2.setEditable(true);
c2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("comboBoxEdited")) {
System.out.println("Adding new player!");
c2.insertItemAt(c2.getSelectedItem(),0);
}
}
});
l10.setBounds(500,150,250,50);
c2.setBounds(750,160,135,30);
l10m=new JLabel("*");
l10m.setBounds(640,150,10,50);
l10m.setForeground(Color.RED);
l11=new JLabel("PLATFORM");
final String [] PF = {"ADM-WPM","ADM-ALIS","ADM-SWeC","ADM-PAS","ADM-BSM","ADM-RAS","ADM-LP&I"};
c5 =new JComboBox(PF);
c5.setEditable(true);
c5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("comboBoxEdited")) {
System.out.println("Adding new player!");
c5.insertItemAt(c5.getSelectedItem(),0);
}
}
});
l11.setBounds(500,200,250,50);
c5.setBounds(750,210,135,30);
l11m=new JLabel("*");
l11m.setBounds(570,200,10,50);
l11m.setForeground(Color.RED);
l12=new JLabel("COMMERCIAL MODEL");
final String [] cml = {"T&M","FP","PSA"};
c3 =new JComboBox(cml);
c3.setEditable(true);
c3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("comboBoxEdited")) {
System.out.println("Adding new player!");
c3.insertItemAt(c3.getSelectedItem(),0);
}
}
});
l12.setBounds(500,250,250,50);
c3.setBounds(750,260,135,30);
l12m=new JLabel("*");
l12m.setBounds(630,250,10,50);
l12m.setForeground(Color.RED);
l13=new JLabel("START DATE");
t13=new JTextField(20);
l13.setBounds(500,300,250,50);
t13.setBounds(750,310,135,30);
t13.setEditable(false);
l13m=new JLabel("*");
l13m.setBounds(580,300,10,50);
l13m.setForeground(Color.RED);
l14=new JLabel("END DATE");
t14=new JTextField(20);
l14.setBounds(500,350,250,50);
t14.setBounds(750,360,135,30);
t14.setEditable(false);
l14m=new JLabel("*");
l14m.setBounds(570,350,10,50);
l14m.setForeground(Color.RED);
l15=new JLabel("CUMULATIVE VALUE OF CONTRACT");
t15=new JTextField(20);
t15.addKeyListener(new KeyAdapter() {
public void keyTyped(KeyEvent e) {
String input=t15.getText();
Pattern p = Pattern.compile("[A-Z,a-z,&%$#@!()*^]");
Matcher m = p.matcher(input);
if (m.find()) {
t15.setText(null);
JOptionPane.showMessageDialog(null, "Please enter only numbers");
}
}});
l15.setBounds(500,400,250,50);
t15.setBounds(750,410,135,30);
l15m=new JLabel("*");
l15m.setBounds(710,400,10,50);
l15m.setForeground(Color.RED);
l16=new JLabel("SOW TRACKER");
l16.setBounds(400,50,250,50);
l16.setFont(new Font("TIMES NEW ROMAN", Font.BOLD, 28));
firstb=new JButton("FIRST");
firstb.setBounds(200,600,100,40);
prev=new JButton("PREVIOUS");
prev.setBounds(400,600,100,40);
nextb=new JButton("NEXT");
nextb.setBounds(600,600,100,40);
lastb=new JButton("LAST");
lastb.setBounds(800,600,100,40);
newb=new JButton("NEW");
newb.setBounds(200,650,100,40);
save=new JButton("SAVE");
save.setBounds(400,650,100,40);
exitb = new JButton("EXIT");
exitb.setBounds(600, 650,100,40);
searchb=new JButton("SEARCH");
searchb.setBounds(800,650,100,40);
b9=new JButton("..");
b9.setBounds(900,315,20,20);
b10=new JButton("..");
b10.setBounds(900,365,20,20);
add(l1);
add(t1);
add(l1m);
add(l2);
add(c6);
add(l2m);
add(l3);
add(t3);
add(l3m);
add(l4);
add(t4);
add(l4m);
add(l5);
add(t5);
add(l5m);
add(l6);
add(c4);
add(l6m);
add(l7);
add(t7);
add(l7m);
add(l8);
add(t8);
add(l9);
add(c1);
add(l9m);
add(l10);
add(c2);
add(l10m);
add(l11);
add(c5);
add(l11m);
add(l12);
add(c3);
add(l12m);
add(l13);
add(t13);
add(l13m);
add(l14);
add(t14);
add(l14m);
add(l15);
add(t15);
add(l15m);
add(l16);
add(firstb);
firstb.addActionListener(this);
add(prev);
prev.addActionListener(this);
add(nextb);
nextb.addActionListener(this);
add(lastb);
lastb.addActionListener(this);
add(newb);
newb.addActionListener(this);
add(save);
save.addActionListener(this);
add(exitb);
exitb.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
add(searchb);
searchb.addActionListener(this);
add(b9);
b9.addActionListener(this);
add(b10);
b10.addActionListener(this);
setSize(1000,1000);
setVisible(true);
setResizable(false);
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource()==save)
{
if(t1.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "Enter CONTRACT REFERENCE NUMBER"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t1.getText()); }}
/*else if(t2.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "Enter CR NUMBER"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t2.getText()); }}*/
else if(t3.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "enter text in JTextField-SOW NAME"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t3.getText()); }}
else if(t4.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "enter text in JTextField-PARTNER SERVICE MANAGER"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t4.getText()); }}
else if(t5.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "enter text in JTextField-LBG SERVICE MANAGER"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t5.getText()); }}
else if(t7.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "Enter VALUE OF CONTRACT"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t7.getText()); }}
/*else if(t11.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "enter text in JTextField-PLATFORM"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t11.getText()); }}
else if(t12.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "enter text in JTextField-COMMERCIAL MODEL"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t12.getText()); }}*/
else if(t13.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "Enter START DATE"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t13.getText()); }}
else if(t14.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "Enter END DATE"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t14.getText()); }}
else if(t15.getText().length()==0) { try{
JOptionPane.showMessageDialog(null, "Enter-CUMULATIVE VALUE OF CONTRACT"); }catch(Exception e){
JOptionPane.showMessageDialog(null, "JTextField is " + t15.getText()); }}
String str1=t13.getText();
String str2=t14.getText();
SimpleDateFormat df = new SimpleDateFormat("dd-MM-yyyy");
Date date1 = null;
try {
date1 = (Date) df.parse(str1);
} catch (ParseException e) {
}
Date date2 = null;
try {
date2 = (Date) df.parse(str2);
} catch (ParseException e) {
}
if (date1.after(date2)) try{
JOptionPane.showMessageDialog(null, "Start Date must be earlier than the end date");
}catch(Exception e){}
if(ae.getSource()==save)
{
try
{
String value1=t1.getText();
String value2=(String)c6.getSelectedItem();
String value3=t3.getText();
String value4=t4.getText();
String value5=t5.getText();
String value6 = (String) c4.getSelectedItem();
String value7=t7.getText();
String value8=t8.getText();
String value9 = (String) c1.getSelectedItem();
String value10 = (String) c2.getSelectedItem();
String value11 = (String) c5.getSelectedItem();
String value12 = (String) c3.getSelectedItem();
String value13=t13.getText();
String value14=t14.getText();
String value15=t15.getText();
Statement st=con.createStatement();
System.out.println(value1);
// String q = "insert into [sheet1$] (CRN,CR_NUM,SOW_N,PSM,LBG,T_CONTRACT,V_CONTRACT,REMARKS,STATUS,APPROVAL,PLATFORM,MODEL,START_D,END_D,CUM_VALUE) values ('12345','"+value2+"','"+value3+"','"+value4+"','"+value5+"','"+value6+"','"+value7+"','"+value8+"','"+value9+"','"+value10+"','"+value11+"','"+value12+"','"+value13+"','"+value14+"','"+value15+"')";
String q = "insert into [sheet1$] values ('"+value1+"','"+value2+"','"+value3+"','"+value4+"','"+value5+"','"+value6+"','"+value7+"','"+value8+"','"+value9+"','"+value10+"','"+value11+"','"+value12+"','"+value13+"','"+value14+"','"+value15+"')";
int ds = st.executeUpdate(q);
System.out.println("Inserted Sucessfully...!!!");
System.out.println(ds);
}catch(Exception e)
{
System.out.println(e.getMessage());
}
finally{
try {
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
else if(ae.getSource()==newb)
{
try{
t1.setText(null);
c6.addItem(null);
t3.setText(null);
t4.setText(null);
t5.setText(null);
c4.addItem(null);
t7.setText(null);
t8.setText(null);
c1.addItem(null);
c2.addItem(null);
c5.addItem(null);
c3.addItem(null);
t13.setText(null);
t14.setText(null);
t15.setText(null);
}catch(Exception e){}
}
else if(ae.getSource()==firstb)
{
try {
rs.first( );
int id_col = rs.getInt("CRN");
String id = Integer.toString(id_col);
//int id_col1 = rs.getInt("CR_NUM");
//String cr= Integer.toString(id_col1);
String cr =rs.getString("CR_NUM");
String sow = rs.getString("SOW_N");
String psm = rs.getString("PSM");
String lbg = rs.getString("LBG");
String toc = rs.getString("T_CONTRACT");
String rm = rs.getString("REMARKS");
String wks = rs.getString("WORK_ST");
String cap = rs.getString("APPROVAL");
String pfm = rs.getString("PLATFORM");
String cmm = rs.getString("MODEL");
String std = rs.getString("START_D");
String etd= rs.getString("END_D");
int id_col2 = rs.getInt("V_CONTRACT");
String voc= Integer.toString(id_col2);
int id_col3 = rs.getInt("CUM_VALUE");
String cvc = Integer.toString(id_col3);
t1.setText(id);
//c6.addItem(cr);
t3.setText(sow);
t4.setText(psm);
t5.setText(lbg);
//c4.addItem(toc);
t7.setText(voc);
t8.setText(rm);
c1.setSelectedItem(wks);
c2.setSelectedItem(cap);
c5.setSelectedItem(pfm);
c3.setSelectedItem(cmm);
c4.setSelectedItem(toc);
c6.setSelectedItem(cr);
//c1.addItem(wks);
//c2.addItem(cap);
//c5.addItem(pfm);
//c3.addItem(cmm);
t13.setText(std);
t14.setText(etd);
t15.setText(cvc);
System.out.println(wks);
}
catch (SQLException err) {
JOptionPane.showMessageDialog(sowui.this, err.getMessage());
}
try{
stmt.close();
}catch(SQLException a) {}
}
else if(ae.getSource()==nextb)
{
try {
if ( rs.next( ) ) {
int id_col = rs.getInt("CRN");
String id = Integer.toString(id_col);
//int id_col1 = rs.getInt("CR_NUM");
//String cr= Integer.toString(id_col1);
String cr =rs.getString("CR_NUM");
String sow = rs.getString("SOW_N");
String psm = rs.getString("PSM");
String lbg = rs.getString("LBG");
String toc = rs.getString("T_CONTRACT");
String rm = rs.getString("REMARKS");
String wks = rs.getString("WORK_ST");
String cap = rs.getString("APPROVAL");
String pfm = rs.getString("PLATFORM");
String cmm = rs.getString("MODEL");
String std = rs.getString("START_D");
String etd= rs.getString("END_D");
int id_col2 = rs.getInt("V_CONTRACT");
String voc= Integer.toString(id_col2);
int id_col3 = rs.getInt("CUM_VALUE");
String cvc = Integer.toString(id_col3);
t1.setText(id);
//c6.addItem(cr);
t3.setText(sow);
t4.setText(psm);
t5.setText(lbg);
//c4.addItem(toc);
t7.setText(voc);
t8.setText(rm);
//c1.addItem(wks);
//c2.addItem(cap);
//c5.addItem(pfm);
//c3.addItem(cmm);
c1.setSelectedItem(wks);
c2.setSelectedItem(cap);
c5.setSelectedItem(pfm);
c3.setSelectedItem(cmm);
c4.setSelectedItem(toc);
c6.setSelectedItem(cr);
t13.setText(std);
t14.setText(etd);
t15.setText(cvc);
}
else {
rs.previous( );
JOptionPane.showMessageDialog(sowui.this, "End of File");
}
}
catch (SQLException err) {
JOptionPane.showMessageDialog(sowui.this, err.getMessage());
}try{
stmt.close();
}catch(SQLException a) {}
}
else if(ae.getSource()==prev)
{
try {
if ( rs.previous( ) ) {
int id_col = rs.getInt("CRN");
String id = Integer.toString(id_col);
//int id_col1 = rs.getInt("CR_NUM");
//String cr= Integer.toString(id_col1);
String cr =rs.getString("CR_NUM");
String sow = rs.getString("SOW_N");
String psm = rs.getString("PSM");
String lbg = rs.getString("LBG");
String toc = rs.getString("T_CONTRACT");
String rm = rs.getString("REMARKS");
String wks = rs.getString("WORK_ST");
String cap = rs.getString("APPROVAL");
String pfm = rs.getString("PLATFORM");
String cmm = rs.getString("MODEL");
String std = rs.getString("START_D");
String etd= rs.getString("END_D");
int id_col2 = rs.getInt("V_CONTRACT");
String voc= Integer.toString(id_col2);
int id_col3 = rs.getInt("CUM_VALUE");
String cvc = Integer.toString(id_col3);
t1.setText(id);
//c6.addItem(cr);
t3.setText(sow);
t4.setText(psm);
t5.setText(lbg);
//c4.addItem(toc);
t7.setText(voc);
t8.setText(rm);
//c1.addItem(wks);
//c2.addItem(cap);
//c5.addItem(pfm);
//c3.addItem(cmm);
c1.setSelectedItem(wks);
c2.setSelectedItem(cap);
c5.setSelectedItem(pfm);
c3.setSelectedItem(cmm);
c4.setSelectedItem(toc);
c6.setSelectedItem(cr);
t13.setText(std);
t14.setText(etd);
t15.setText(cvc);
}
else {
rs.next( );
JOptionPane.showMessageDialog(sowui.this, "Top of File");
}
}
catch (SQLException err) {
JOptionPane.showMessageDialog(sowui.this, err.getMessage());
}try{
stmt.close();
}catch(SQLException a) {}
}
if(ae.getSource()==lastb)
{
try {
rs.last( );
int id_col = rs.getInt("CRN");
String id = Integer.toString(id_col);
//int id_col1 = rs.getInt("CR_NUM");
//String cr= Integer.toString(id_col1);
String cr =rs.getString("CR_NUM");
String sow = rs.getString("SOW_N");
String psm = rs.getString("PSM");
String lbg = rs.getString("LBG");
String toc = rs.getString("T_CONTRACT");
String rm = rs.getString("REMARKS");
String wks = rs.getString("WORK_ST");
String cap = rs.getString("APPROVAL");
String pfm = rs.getString("PLATFORM");
String cmm = rs.getString("MODEL");
String std = rs.getString("START_D");
String etd= rs.getString("END_D");
int id_col2 = rs.getInt("V_CONTRACT");
String voc= Integer.toString(id_col2);
int id_col3 = rs.getInt("CUM_VALUE");
String cvc = Integer.toString(id_col3);
t1.setText(id);
//c6.addItem(cr);
t3.setText(sow);
t4.setText(psm);
t5.setText(lbg);
//c4.addItem(toc);
t7.setText(voc);
t8.setText(rm);
//c1.addItem(wks);
//c2.addItem(cap);
//c5.addItem(pfm);
//c3.addItem(cmm);
c1.setSelectedItem(wks);
c2.setSelectedItem(cap);
c5.setSelectedItem(pfm);
c3.setSelectedItem(cmm);
c4.setSelectedItem(toc);
c6.setSelectedItem(cr);
t13.setText(std);
t14.setText(etd);
t15.setText(cvc);
}
catch (SQLException err) {
JOptionPane.showMessageDialog(sowui.this, err.getMessage());
}try{
stmt.close();
}catch(SQLException a) {}
}
答案 0 :(得分：3)
除了评论中已经设置的内容之外，还有一些关于您发布的代码的其他评论：
setLayout( null )来电和所有相关电话（setBounds等）。而是Learn to use Layout Managers。ResultSet实例）。有关详细信息，请参阅Concurrency in Swing教程JTextComponent的输入（在您的代码中，变量名为t1和t3）不应使用KeyListener。 Use a DocumentFilter instead，如果是文字字段consider using a JFormattedTextField。例如，在文本字段中拖放输入将完全绕过KeyListener。getSource()方法，该方法允许检索发生事件的源组件。这可以避免大量的代码重复，因为你有多个侦听器完全相同的事情。它们不同的唯一部分是源组件，可以从事件中检索。另一个选择是从匿名类切换到内部类，并在构造函数中传递所需的信息。try{} catch ( Exception e )围绕随机代码片段然后不做任何错误处理就是要求将来出现奇怪的错误。您可以正确处理Exception，也可以进一步处理它。catch块甚至更糟。现在你默默地忽略了错误，代码更进一步，没有任何反应。谁知道你的计划将以什么状态结束答案 1 :(得分：2)
结果集绑定到您的语句和连接。当您仍然打开数据库连接时，应该读取ResultSet的内容，然后关闭结果集，语句，然后关闭连接。
请注意，您不必将结果读取到UI - 您也可以将它们读入某个内部集合，然后在需要时更新UI。只需将它们从结果集中取出，同时仍然可以对所提到的对象进行引用。